Answer:
Molecules stop moving at freezing point. Helium has the lowest boiling point. The molecules move very quickly at boiling point.
Explanation:
Heating up- molecules move faster. Cooling down- molecules move slower
Answer: Neurone
Explanation:
Neurone is also known as nerve cell. It is the basic unit of the nervous system, and helps to transmits/ conducts nerve impulses from the brain to the body or vice versa.
Answer:
The commensal relationship between the sharks and remoras can be described as although remoras consume parasites, sharks with remoras show no better health or growth than sharks without remoras.
Explanation:
A commensal relationship refers to a relationship where two or more organisms in a habitat neither benefit or harm each other.
- The second option infers that the remoras harm the sharks. This is a parasitic relationship.
- The third option infers that the sharks are harmed by the remoras because the sharks depend on something that the remoras are limiting. This is also a parasitic relationship.
- The fourth option infers a commensal relationship, but falsely describes it. The relationship described by this option is a parasitic relationship (one benefits, the other does not).
Therefore, the answer is the first option: Although remoras consume parasites, sharks with remoras show no better health or growth than sharks without remoras.
Answer:
1. The difference between the normal hemoglobin protein DNA sequence and the sickle cell hemoglobin DNA sequence is a base to base shift, in this case adenine (GAG) to thymine (GTG).
2. The difference affects the amino acid sequence of the protein by replacing glutamic acid (Glu) with valine (Val).
Explanation:
In sickle cell anemia, a change in the DNA nucleotide sequence is observed, where adenine is substituted by thymine, whose expression is the change in the amino acid sequence of globine β, incorporating valine instead of glutamic acid. This represents a molecular mutation - point mutation - by subtitution, which corresponds to missense mutation.
<u>Normal hemoglobin protein in a RBC</u>
DNA CTG ACT CCT GAG GAG AAG TCT
Amino acids Leu Thr Pro Glu Glu Lys Ser
<u>Sickle cell hemoglobin protein in a RBC</u>
DNA CTG ACT CCT <em>GTG</em> GAG AAG TCT
Amino acids Leu Thr Pro <em>Val</em> Glu Lys Ser
When GAG is transcribed to mRNA, the CUC codon is obtained, which codes for glutamic acid. Thymine substitution causes the DNA sequence to change to GTG, which is transcribed as CAC, the codon that encodes the amino acid valine. The <u>change from glutamic acid to valine in β-globin causes an altered hemoglobin, giving the abnormal erythrocytes observed in sickle cell disease</u>.
